[PATCH v3 02/17] KVM: PPC: Book3S HV: add a new KVM device for the XIVE native exploitation mode
Cédric Le Goater
clg at kaod.org
Fri Mar 15 23:05:54 AEDT 2019
This is the basic framework for the new KVM device supporting the XIVE
native exploitation mode. The user interface exposes a new KVM device
to be created by QEMU, only available when running on a L0 hypervisor
only. Support for nested guests is not available yet.
The XIVE device reuses the device structure of the XICS-on-XIVE device
as they have a lot in common. That could possibly change in the future
if the need arise.
Signed-off-by: Cédric Le Goater <clg at kaod.org>
---
Changes since v2:
- removed ->q_order setting. Only useful in the XICS-on-XIVE KVM
device which allocates the EQs on behalf of the guest.
- returned -ENXIO when VP base is invalid
arch/powerpc/include/asm/kvm_host.h | 1 +
arch/powerpc/include/asm/kvm_ppc.h | 8 +
arch/powerpc/include/uapi/asm/kvm.h | 3 +
include/uapi/linux/kvm.h | 2 +
arch/powerpc/kvm/book3s.c | 7 +-
arch/powerpc/kvm/book3s_xive_native.c | 184 +++++++++++++++++++++
Documentation/virtual/kvm/devices/xive.txt | 19 +++
arch/powerpc/kvm/Makefile | 2 +-
8 files changed, 224 insertions(+), 2 deletions(-)
create mode 100644 arch/powerpc/kvm/book3s_xive_native.c
create mode 100644 Documentation/virtual/kvm/devices/xive.txt
diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h
index 091430339db1..9f75a75a07f2 100644
--- a/arch/powerpc/include/asm/kvm_host.h
+++ b/arch/powerpc/include/asm/kvm_host.h
@@ -220,6 +220,7 @@ extern struct kvm_device_ops kvm_xics_ops;
struct kvmppc_xive;
struct kvmppc_xive_vcpu;
extern struct kvm_device_ops kvm_xive_ops;
+extern struct kvm_device_ops kvm_xive_native_ops;
struct kvmppc_passthru_irqmap;
diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h
index b3bf4f61b30c..4b72ddde7dc1 100644
--- a/arch/powerpc/include/asm/kvm_ppc.h
+++ b/arch/powerpc/include/asm/kvm_ppc.h
@@ -593,6 +593,10 @@ extern int kvmppc_xive_set_icp(struct kvm_vcpu *vcpu, u64 icpval);
extern int kvmppc_xive_set_irq(struct kvm *kvm, int irq_source_id, u32 irq,
int level, bool line_status);
extern void kvmppc_xive_push_vcpu(struct kvm_vcpu *vcpu);
+
+extern void kvmppc_xive_native_init_module(void);
+extern void kvmppc_xive_native_exit_module(void);
+
#else
static inline int kvmppc_xive_set_xive(struct kvm *kvm, u32 irq, u32 server,
u32 priority) { return -1; }
@@ -616,6 +620,10 @@ static inline int kvmppc_xive_set_icp(struct kvm_vcpu *vcpu, u64 icpval) { retur
static inline int kvmppc_xive_set_irq(struct kvm *kvm, int irq_source_id, u32 irq,
int level, bool line_status) { return -ENODEV; }
static inline void kvmppc_xive_push_vcpu(struct kvm_vcpu *vcpu) { }
+
+static inline void kvmppc_xive_native_init_module(void) { }
+static inline void kvmppc_xive_native_exit_module(void) { }
+
#endif /* CONFIG_KVM_XIVE */
#ifdef CONFIG_PPC_POWERNV
diff --git a/arch/powerpc/include/uapi/asm/kvm.h b/arch/powerpc/include/uapi/asm/kvm.h
index 8c876c166ef2..b002c0c67787 100644
--- a/arch/powerpc/include/uapi/asm/kvm.h
+++ b/arch/powerpc/include/uapi/asm/kvm.h
@@ -675,4 +675,7 @@ struct kvm_ppc_cpu_char {
#define KVM_XICS_PRESENTED (1ULL << 43)
#define KVM_XICS_QUEUED (1ULL << 44)
+/* POWER9 XIVE Native Interrupt Controller */
+#define KVM_DEV_XIVE_GRP_CTRL 1
+
#endif /* __LINUX_KVM_POWERPC_H */
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index 6d4ea4b6c922..e6368163d3a0 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -1211,6 +1211,8 @@ enum kvm_device_type {
#define KVM_DEV_TYPE_ARM_VGIC_V3 KVM_DEV_TYPE_ARM_VGIC_V3
KVM_DEV_TYPE_ARM_VGIC_ITS,
#define KVM_DEV_TYPE_ARM_VGIC_ITS KVM_DEV_TYPE_ARM_VGIC_ITS
+ KVM_DEV_TYPE_XIVE,
+#define KVM_DEV_TYPE_XIVE KVM_DEV_TYPE_XIVE
KVM_DEV_TYPE_MAX,
};
diff --git a/arch/powerpc/kvm/book3s.c b/arch/powerpc/kvm/book3s.c
index 601c094f15ab..96d43f091255 100644
--- a/arch/powerpc/kvm/book3s.c
+++ b/arch/powerpc/kvm/book3s.c
@@ -1040,6 +1040,9 @@ static int kvmppc_book3s_init(void)
if (xics_on_xive()) {
kvmppc_xive_init_module();
kvm_register_device_ops(&kvm_xive_ops, KVM_DEV_TYPE_XICS);
+ kvmppc_xive_native_init_module();
+ kvm_register_device_ops(&kvm_xive_native_ops,
+ KVM_DEV_TYPE_XIVE);
} else
#endif
kvm_register_device_ops(&kvm_xics_ops, KVM_DEV_TYPE_XICS);
@@ -1050,8 +1053,10 @@ static int kvmppc_book3s_init(void)
static void kvmppc_book3s_exit(void)
{
#ifdef CONFIG_KVM_XICS
- if (xics_on_xive())
+ if (xics_on_xive()) {
kvmppc_xive_exit_module();
+ kvmppc_xive_native_exit_module();
+ }
#endif
#ifdef CONFIG_KVM_BOOK3S_32_HANDLER
kvmppc_book3s_exit_pr();
diff --git a/arch/powerpc/kvm/book3s_xive_native.c b/arch/powerpc/kvm/book3s_xive_native.c
new file mode 100644
index 000000000000..76d45bcc7060
--- /dev/null
+++ b/arch/powerpc/kvm/book3s_xive_native.c
@@ -0,0 +1,184 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2017-2019, IBM Corporation.
+ */
+
+#define pr_fmt(fmt) "xive-kvm: " fmt
+
+#include <linux/anon_inodes.h>
+#include <linux/kernel.h>
+#include <linux/kvm_host.h>
+#include <linux/err.h>
+#include <linux/gfp.h>
+#include <linux/spinlock.h>
+#include <linux/delay.h>
+#include <linux/percpu.h>
+#include <linux/cpumask.h>
+#include <asm/uaccess.h>
+#include <asm/kvm_book3s.h>
+#include <asm/kvm_ppc.h>
+#include <asm/hvcall.h>
+#include <asm/xics.h>
+#include <asm/xive.h>
+#include <asm/xive-regs.h>
+#include <asm/debug.h>
+#include <asm/debugfs.h>
+#include <asm/time.h>
+#include <asm/opal.h>
+
+#include <linux/debugfs.h>
+#include <linux/seq_file.h>
+
+#include "book3s_xive.h"
+
+static int kvmppc_xive_native_set_attr(struct kvm_device *dev,
+ struct kvm_device_attr *attr)
+{
+ switch (attr->group) {
+ case KVM_DEV_XIVE_GRP_CTRL:
+ break;
+ }
+ return -ENXIO;
+}
+
+static int kvmppc_xive_native_get_attr(struct kvm_device *dev,
+ struct kvm_device_attr *attr)
+{
+ return -ENXIO;
+}
+
+static int kvmppc_xive_native_has_attr(struct kvm_device *dev,
+ struct kvm_device_attr *attr)
+{
+ switch (attr->group) {
+ case KVM_DEV_XIVE_GRP_CTRL:
+ break;
+ }
+ return -ENXIO;
+}
+
+static void kvmppc_xive_native_free(struct kvm_device *dev)
+{
+ struct kvmppc_xive *xive = dev->private;
+ struct kvm *kvm = xive->kvm;
+
+ debugfs_remove(xive->dentry);
+
+ pr_devel("Destroying xive native device\n");
+
+ if (kvm)
+ kvm->arch.xive = NULL;
+
+ if (xive->vp_base != XIVE_INVALID_VP)
+ xive_native_free_vp_block(xive->vp_base);
+
+ kfree(xive);
+ kfree(dev);
+}
+
+static int kvmppc_xive_native_create(struct kvm_device *dev, u32 type)
+{
+ struct kvmppc_xive *xive;
+ struct kvm *kvm = dev->kvm;
+ int ret = 0;
+
+ pr_devel("Creating xive native device\n");
+
+ if (kvm->arch.xive)
+ return -EEXIST;
+
+ xive = kzalloc(sizeof(*xive), GFP_KERNEL);
+ if (!xive)
+ return -ENOMEM;
+
+ dev->private = xive;
+ xive->dev = dev;
+ xive->kvm = kvm;
+ kvm->arch.xive = xive;
+
+ /*
+ * Allocate a bunch of VPs. KVM_MAX_VCPUS is a large value for
+ * a default. Getting the max number of CPUs the VM was
+ * configured with would improve our usage of the XIVE VP space.
+ */
+ xive->vp_base = xive_native_alloc_vp_block(KVM_MAX_VCPUS);
+ pr_devel("VP_Base=%x\n", xive->vp_base);
+
+ if (xive->vp_base == XIVE_INVALID_VP)
+ ret = -ENXIO;
+
+ xive->single_escalation = xive_native_has_single_escalation();
+
+ if (ret)
+ kfree(xive);
+
+ return ret;
+}
+
+static int xive_native_debug_show(struct seq_file *m, void *private)
+{
+ struct kvmppc_xive *xive = m->private;
+ struct kvm *kvm = xive->kvm;
+
+ if (!kvm)
+ return 0;
+
+ return 0;
+}
+
+static int xive_native_debug_open(struct inode *inode, struct file *file)
+{
+ return single_open(file, xive_native_debug_show, inode->i_private);
+}
+
+static const struct file_operations xive_native_debug_fops = {
+ .open = xive_native_debug_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
+
+static void xive_native_debugfs_init(struct kvmppc_xive *xive)
+{
+ char *name;
+
+ name = kasprintf(GFP_KERNEL, "kvm-xive-%p", xive);
+ if (!name) {
+ pr_err("%s: no memory for name\n", __func__);
+ return;
+ }
+
+ xive->dentry = debugfs_create_file(name, 0444, powerpc_debugfs_root,
+ xive, &xive_native_debug_fops);
+
+ pr_debug("%s: created %s\n", __func__, name);
+ kfree(name);
+}
+
+static void kvmppc_xive_native_init(struct kvm_device *dev)
+{
+ struct kvmppc_xive *xive = (struct kvmppc_xive *)dev->private;
+
+ /* Register some debug interfaces */
+ xive_native_debugfs_init(xive);
+}
+
+struct kvm_device_ops kvm_xive_native_ops = {
+ .name = "kvm-xive-native",
+ .create = kvmppc_xive_native_create,
+ .init = kvmppc_xive_native_init,
+ .destroy = kvmppc_xive_native_free,
+ .set_attr = kvmppc_xive_native_set_attr,
+ .get_attr = kvmppc_xive_native_get_attr,
+ .has_attr = kvmppc_xive_native_has_attr,
+};
+
+void kvmppc_xive_native_init_module(void)
+{
+ ;
+}
+
+void kvmppc_xive_native_exit_module(void)
+{
+ ;
+}
diff --git a/Documentation/virtual/kvm/devices/xive.txt b/Documentation/virtual/kvm/devices/xive.txt
new file mode 100644
index 000000000000..fdbd2ff92a88
--- /dev/null
+++ b/Documentation/virtual/kvm/devices/xive.txt
@@ -0,0 +1,19 @@
+POWER9 eXternal Interrupt Virtualization Engine (XIVE Gen1)
+==========================================================
+
+Device types supported:
+ KVM_DEV_TYPE_XIVE POWER9 XIVE Interrupt Controller generation 1
+
+This device acts as a VM interrupt controller. It provides the KVM
+interface to configure the interrupt sources of a VM in the underlying
+POWER9 XIVE interrupt controller.
+
+Only one XIVE instance may be instantiated. A guest XIVE device
+requires a POWER9 host and the guest OS should have support for the
+XIVE native exploitation interrupt mode. If not, it should run using
+the legacy interrupt mode, referred as XICS (POWER7/8).
+
+* Groups:
+
+ 1. KVM_DEV_XIVE_GRP_CTRL
+ Provides global controls on the device
diff --git a/arch/powerpc/kvm/Makefile b/arch/powerpc/kvm/Makefile
index 64f1135e7732..806cbe488410 100644
--- a/arch/powerpc/kvm/Makefile
+++ b/arch/powerpc/kvm/Makefile
@@ -99,7 +99,7 @@ endif
kvm-book3s_64-objs-$(CONFIG_KVM_XICS) += \
book3s_xics.o
-kvm-book3s_64-objs-$(CONFIG_KVM_XIVE) += book3s_xive.o
+kvm-book3s_64-objs-$(CONFIG_KVM_XIVE) += book3s_xive.o book3s_xive_native.o
kvm-book3s_64-objs-$(CONFIG_SPAPR_TCE_IOMMU) += book3s_64_vio.o
kvm-book3s_64-module-objs := \
--
2.20.1
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